Methane capture churns cheesemaking operation
Published 26/04/2011 | 05:00
A short trip across the German border into Austria, again at the foothills of the Alps, we visited dairy farmers and cheesemakers Toni and Martha Fahringer.
Like so many farm dwellings in rural Germany and Austria, their house, cheese factory and cattle were all under one roof, albeit a very large roof.
When renovating their cow shed two years ago, they decided to install a biogas unit to supply the heat requirements for the cheesemaking process.
There are several different types of cheese produced by the Fahringer's, in total amounting to a yearly production of 8,000kg.
All the cheese is produced from milk from their own cow herd. In total, 35 Simmental cows yield 6,000 litres of milk each a year. They are fed on hay cut three times a year from the farm's 25ha down in the valley.
The family also has 35ha on the slopes of the Alps, where in spring and summer the cows graze these pastures. It is the grasses and herbs from these slopes that gives the milk and cheeses their distinctive flavours.
Despite having four stomachs, cows cannot digest grass completely efficiently. It is this undigested part of their feed that breaks down even further in the anaerobic digester to produce methane gas.
At the dirty end of the anaerobic digestion process, an enclosed shuttered concrete slurry tank provides the environment that is required to produce and capture methane gas.